Unfortunately, there are 252 countries in the world, of which only 23 are highly developed. What is important for a country is, first of all, the economy, the amount of mineral resources and the population. There is one paradox: Nigeria has a huge amount of oil, but the people are very poor. This can be explained by the fact that Nigeria has a very high level of corruption, insufficient economic development and low levels of health care. And all these problems led to the development of fraud, robbery and violence.
I would not only focus on talking on Nigeria, you know. Those things you are saying about Nigeria are likely true (it is something I have read being repeated here in the forum quite often by people from that country), but you are given the fake perceptions that it is true most of scammers are from Nigeria or at the very least you are giving some implicit justification for people going through economical hardship to scamm people around the world, which is not right.
Also, you should consider that even in developed countries like the United States, there is an important percentage of people who are characterized as homeless and can barely survive by living in the sewers of the big cities like Las Vegas.
There is poverty and desperation in all countries, the difference is the percentage willing to scam on the internet and also those who would rather to live off welfare (if possible). let us not to continue to fuel the myth all scammers are from a single country or region, it does not do any good favor to the honest people of those places.